Honing tool and method for machining a bearing part

ABSTRACT

A honing tool includes a honing stone holder and a branching lubricant duct arranged in the honing stone holder. The branching lubricant duct has a straight section, first and second diagonal sections connected to and positioned diagonally to the straight section, and first and second transition sections that adjoin the first and second diagonal sections, respectively, and are arranged in a first plane parallel to and spaced from the straight section. The duct also has first and second open end sections continuing from the first and second transition sections, respectively, and directed towards a second plane arranged parallel to the first plane and in which the straight section is situated. In an example embodiment, the honing tool includes a honing stone fixed in the honing stone holder between the first and second transition sections.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is the United States National Phase of PCT Appln. No.PCT/DE2020/100865 filed Oct. 6, 2020, which claims priority to GermanApplication No. DE102019129874.1 filed Nov. 6, 2019, the entiredisclosures of which are incorporated by reference herein.

TECHNICAL FIELD

The present disclosure relates to a honing tool that enables coolinglubricant to be supplied to a workpiece. The disclosure further relatesto a method for machining a bearing part, in particular a wheel bearing,by honing.

BACKGROUND

A honing tool is known, for example, from DE 33 36 626 A1. The knownhoning tool is provided for connection to a pressurized honing oilsource. The honing oil is intended to wash away abrasion from the worksurface of a honing stone.

Another honing device that includes a supply duct for a cutting fluid isdisclosed in CN 202399128 U. The supply duct for cutting fluid has aninlet and a double outlet.

A device known from DE 10 2009 040 062 A1 for finishing ring-shapedworkpieces, in particular bearing rings, includes a device forshort-stroke honing, which has an oscillation drive for generatingoscillatory movements of a honing stone holder. Furthermore, a toolholder is provided, which is designed to accommodate a hard turningtool.

A further device for mechanical finishing of surfaces on rotationallysymmetrical workpieces is described in DE 10 2007 054 897 B4. Theworkpiece to be machined can be a bearing ring for a double-rowspherical roller bearing. A tool carrier of the known machining devicecan carry out both short-stroke oscillating movements and long-strokeoscillating movements with the aid of various drives.

SUMMARY

The present disclosure provides a honing tool and a method formachining, namely honing, of a bearing part, in particular a wheelbearing. The configurations and advantages explained below in connectionwith the machining method also apply analogously to the honing tool, andvice versa.

The honing tool includes a honing stone holder, in which a branchinglubricant duct is situated, which has a first, straight section, twosections which are connected to and positioned diagonally to the firstsection, and two transition sections which adjoin these diagonallypositioned sections and are arranged in a plane parallel to and spacedfrom the first section. Open end sections continue from the transitionsections, said end sections being directed in the sense of surfacenormals towards a plane which is parallel to the aforementioned planedefined by the position of the transition sections and in which thefirst section of the lubricant duct is situated. The term transitionsections was chosen for distinction from the other sections of thelubricant duct and does not imply any information about a deviatinggeometric design of the transition sections.

With this design of the lubricant duct in the honing stone holder, whichdescribes a forked shape, it is possible to use one and the same honingtool, e.g., with unchanged mounting of the honing stone in the honingstone holder, for honing both rolling bearing raceways of an outer ringof a wheel bearing for a motor vehicle. With regard to movements of thehoning tool and of the workpiece or bearing part, e.g., the wheelbearing outer ring, during machining, common processes can in principlebe implemented during honing.

In general, the honing process includes the following steps:

providing a bearing part, e.g., a wheel bearing, namely a one-pieceouter ring, through which two raceways for rolling elements are formed,

providing a honing tool which is formed from a cranked holder and ahoning stone fixed therein. The longitudinal direction of the holder isgiven by a shaft of the holder and the honing stone is designed as anelongate cuboid that forms a right angle with the longitudinal directionof the holder. The holder is traversed by a lubricant duct branching outwithin the holder, the outlet openings of which lubricant duct arearranged next to the honing stone,

machining the first raceway of the outer ring with the honing tool.Cooling lubricant is passed through the lubricant duct and directed inthe longitudinal direction of the honing stone onto the surface beingmachined, and

machining the second raceway of the outer ring with the honing tool.Again cooling lubricant is passed through the lubricant duct anddirected in the longitudinal direction of the honing stone onto thesurface being machined.

The indication “elongate cuboid” in connection with the honing stonerefers to its basic shape. In the machining area in particular, theshape of the honing stone can deviate from a cuboid shape.

With regard to the design of an outer ring of a wheel bearing, referenceis made, for example, to DE 10 2009 051 930 A1. Wheel bearings with morethan two rows of rolling elements, as disclosed, for example, in DE 102010 055 405 A1, can also be machined with the honing tool.

The cranked shape of the honing stone holder, which allows honing bothraceways of a commercially available wheel bearing, is evident both inthe overall shape of the honing stone holder and in the course of thepartially split lubricant duct running in the honing stone holder. Thehoning stone may be fixed in the honing stone holder between the twotransition sections of the lubricant duct lying in a common plane andparallel to the first section. For fixing the honing stone, a pressureblock that is arranged inside the honing stone holder and can beadjusted with a screw mechanism may be used.

The two end sections of the lubricant duct, from which the coolinglubricant used in the honing emerges, are typically aligned in thelongitudinal direction of the honing stone and thus transversely to theshaft of the honing stone holder. The first straight section of thelubricant duct, i.e., running in the shaft, is typically longer than anyother section of the lubricant duct. In contrast, the two end sectionsmay be the shortest sections of the lubricant duct.

The two diagonally positioned sections may be connected to the firstsection via a transverse section oriented orthogonally to the firstsection. In a manner that is advantageous in terms of manufacturingtechnology, as far as the manufacture of the honing stone holder isconcerned, the transverse section, like the two diagonally positionedsections, is closed on one side by a screw.

The honing tool can be used particularly efficiently in that it can beattached to and partially inserted into the outer ring from the same endface of the outer ring one after the other for machining the firstraceway of an outer ring and for machining the second raceway of theouter ring. The machined bearing part for a wheel bearing is typically arolling bearing designed as a two-row ball bearing.

BRIEF DESCRIPTION OF THE DRAWINGS

In the following, an exemplary embodiment of the disclosure is explainedin more detail by means of a drawing. In the figures:

FIG. 1 shows a honing stone holder of a honing tool in a perspectiveview,

FIG. 2 shows the honing stone holder in a sectional view,

FIG. 3 shows the machining of a wheel bearing outer ring with the honingtool in a first machining phase, and

FIG. 4 shows the machining of the wheel bearing outer ring by the honingtool in a second machining phase.

DETAILED DESCRIPTION

A honing tool, identified as a whole by reference sign 3, is providedfor machining a workpiece 2, namely the wheel bearing outer ring. Thearrangement sketched in FIGS. 3 and 4, which comprises the workpiece 2,i.e., the wheel bearing part, and the honing tool 3, is referred to as awhole as a machining arrangement 1. In FIG. 3, a pressure roller 6 canalso be seen, which absorbs radial forces.

The workpiece 2 to be machined has a flange 4 which, when the wheelbearing is installed, is connected to a wheel carrier. Bores in theflange 4 are denoted by 5. The flange 4 is connected in one piece to acylindrical section 12 in which a first raceway 10 and a second raceway11 are formed, which are to be machined with the honing tool 3. In thefinished state of the wheel bearing, balls roll as rolling elements onthe raceways 10, 11 in a manner known per se. Overall, the wheelbearing, which comprises the wheel bearing part 2, is designed as adouble-row angular contact roller bearing in an O-arrangement. Withregard to the basic construction of such a wheel bearing, reference ismade to the prior art cited at the outset.

The honing tool 3 comprises a honing stone holder 7, shown in isolationin FIGS. 1 and 2, which is also referred to as a holder for short. Whenusing the honing tool 3, a honing stone 8 is fixed in the holder 7 withthe aid of a pressure block 9. The honing stone holder 7 is traversed bya duct, denoted as a whole by 16, partially split into two arms, i.e., alubricant duct, which will be discussed in more detail below.

A cooling lubricant 13, which is also referred to as lubricant for shortand is used for honing, is passed through the duct 16. The lubricant 13is introduced through a connection piece 18 into a straight, longsection 17 of the duct 16. The first, straight section 17 of the duct 16runs through a shaft 15 of the honing stone holder 7. At its endopposite the connection piece 18, the shaft 15 merges into a widenedsection 19. In this widened section 19 there is a transverse duct 20which adjoins the first section 17 and is also assigned to the duct 16.The two ends of the transverse duct 20 are connected to diagonal ducts23, 24, which are located in an intermediate section 22 which bendsobliquely from the area of the holder 7 formed from the shaft 15 and thewidened section 19 connected thereto.

The transverse duct 20, which is also referred to as a transversesection, is designed as a blind hole closed by a screw 21 on a sidesurface of the holder 7. In a corresponding manner, the two diagonalducts 23, 24, i.e., diagonally positioned sections of the lubricant duct16, are closed by screws 25, 26.

The diagonally positioned sections 23, 24 each merge into a straight,short section 27, 28 shortly before the screws 25, 26. The two straight,short sections 27, 28 are also referred to as transition sections anddefine a plane which is arranged parallel to a plane in which the first,straight section 17 of the duct 16 is situated. Each of the shortsections 27, 28 is closed by a screw 29, 30 which—based on thearrangement according to FIG. 1—is arranged on the underside of thehoning stone holder 7.

Above the screws 29, 30, one end section 31, 32 branches off at rightangles from the straight, short sections 27, 28. The cooling lubricant13 emerges from the end sections 31, 32 in such a way that it is fed tothe machining area along the honing stone 8. The two machining areas,which are in the form of the raceways 10, 11, are separated from oneanother by a central inner wall area 14. Due to the cranked shape of thehoning stone holder 7 including the lubricant duct 16, each raceway 10,11 can be reached from the same end face of the workpiece 2, wherein thelubricant 13 is supplied to the respective machining area in a targetedmanner in each case.

REFERENCE NUMERALS

1 Machining arrangement

2 Bearing part, workpiece

3 Honing tool

4 Flange

5 Bore

6 Pressure roller

7 Holder, honing stone holder

8 Honing stone

9 Pressure block

10 First raceway

11 Second raceway

12 Cylindrical section of the workpiece

13 Lubricant

14 Central inner wall area

15 Shaft

16 Duct, lubricant duct

17 Straight, long section

18 Connector

19 Widened section

20 Transverse duct, transverse section

21 Screw

77 Intermediate section

23 Diagonally positioned section of the duct

24 Diagonally positioned section of the duct

25 Screw

26 Screw

27 Straight, short section, transition section

28 Straight, short section, transition section

29 Screw

30 Screw

31 End section

32 End section

1-8. (canceled)
 9. A honing tool comprising: a honing stone holder; anda branching lubricant duct arranged in the honing stone holder, thebranching lubricant duct comprising: a straight section; a firstdiagonal section connected to and positioned diagonally to the straightsection; a second diagonal section connected to and positioneddiagonally to the straight section; a first transition section thatadjoins the first diagonal section and is arranged in a first planeparallel to and spaced from the straight section; a second transitionsection that adjoins the second diagonal section and is arranged in thefirst plane; a first open end section continuing from the firsttransition section and directed towards a second plane arranged parallelto the first plane and in which the straight section is situated; and asecond open end section continuing from the second transition sectionand directed towards the second plane.
 10. The honing tool of claim 9,further comprising a honing stone fixed in the honing stone holderbetween the first transition section and the second transition section.11. The honing tool of claim 10, wherein: the honing stone comprises alongitudinal direction; and the first open end section and the secondopen end section are oriented in the longitudinal direction.
 12. Thehoning tool of claim 9, wherein: the straight section is longer than allother sections of the branching lubricant duct; and the first open endsection and the second open end section are shorter than all othersections of the branching lubricant duct.
 13. The honing tool of claim9, wherein: the branching lubricant duct further comprises a transversesection oriented orthogonally to the straight section; and each of thefirst diagonal section and the second diagonal section is connected tothe straight section via the transverse section.
 14. The honing tool ofclaim 13, wherein each of the transverse section, the first diagonalsection and the second diagonal section is closed on one side by arespective screw.
 15. A method for machining a bearing part comprising:providing the bearing part comprising a first raceway and a secondraceway for rolling elements; providing a honing tool formed from acranked holder and a honing stone fixed therein, wherein: the crankedholder comprises: a shaft; a longitudinal direction extending along theshaft; and a branching lubricant duct with outlet openings arranged nextto the honing stone; the honing stone is designed as an elongate cuboidthat forms a right angle with the longitudinal direction; and machiningthe first raceway with the honing tool, wherein a cooling lubricant ispassed through the branching lubricant duct and directed in thelongitudinal direction onto the first raceway; and machining the secondraceway with the honing tool, wherein the cooling lubricant is passedthrough the branching lubricant duct and directed in the longitudinaldirection onto the second raceway.
 16. The method of claim 15 whereinthe bearing part is for a wheel bearing.
 17. The method of claim 15wherein the bearing part is an outer ring for a wheel bearing.
 18. Themethod of claim 15, wherein: during the machining of the first racewaywith the honing tool, the honing tool engages in the bearing part from afirst end face; and during the machining of the second raceway with thehoning tool, the honing tool engages in the bearing part from the firstend face.